The clinical complications of diabetes manifest themselves in both skeletal and non-skeletal connective tissue. Despite the extensive literature relating to the complications observed for non-skeletal tissues in diabetes, the metabolic changes occurring in bone and cartilage have received little attention. Studies from our current proposal suggest that in long-term diabetes articular cartilage undergoes morphological and metabolic changes similar to those observed in degenerative joint disease. These changes are not apparent in short-term diabetic cartilage. In this proposal we plan to examine the chemical and physical characteristics of proteoglycans obtained from rat articular cartilage of control, diabetic and insulin-treated diabetic animals over a nine month period. Cartilage proteoglycans will be isolated and characterized using newly developed semi-micro procedures particularly developed for the studies outlined in this proposal. In addition, recently developed immunological procedures which use monoclonal antibodies that specifically recognize proteoglycan aggregate substructures will be used to identify and quantitate proteoglycan components in articular cartilage from normal and experimental animals. Proteoglycan metabolism in Swarm rat chondrosarcomas grown in control, diabetic and insulin-treated diabetic animals will also be studied. In these studies, large amounts of material will be available for detailed biochemical characterization of proteoglycans produced in each experimental animal. The in vivo and in vitro incorporation of radiolabelled metabolic precursors will be studied to determine whether the rate of proteoglycan synthesis is significantly affected by the diabetic condition. Semi-micro isolation procedures will be used to characterize the newly synthesized proteoglycans and immunological procedures using affinity columns made from characterized monoclonal antibody preparations will be used to quantitate any changes in the rate of synthesis of specific proteoglycan components. The long-term objective of this proposal is to extend these studies to the examination of proteoglycan metabolism in other more complex connective tissue in diabetes (e.g. aorta, the eye and skin) to see if any changes occur which contribute significantly to the complications that become evident in the later stages of the disease.